mutation

point mutation a mutation resulting from a change in a single base pair in the DNA molecule.

somatic mutation a genetic mutation occurring in a somatic cell, providing the basis for mosaicism.

suppressor mutation the correction of the effect of a mutation at one locus by a mutation at another locus.

so·mat·ic mu·ta·tion

a mutation occurring in the general body cells (as opposed to the germ cells) and hence not transmitted to progeny.

somatic mutation

Etymology: Gk, soma, body; L, mutare, to change

a sudden change in the chromosomal material in somatic cell nuclei affecting derived cells but not offspring.

Acquired Mutation

Genetics A post-meiotic alteration in a DNA sequence, which can be passed to the mutated cell’s progeny and linked to the development of cancer.Molecular biology A non-heritable genetic change in a somatic cell; a somatic mutation.

so·mat·ic mu·ta·tion

(sō-mat'ik myū-tā'shŭn)

A change that occurs in the general body cells (as opposed to the germ cells) and hence not transmitted to progeny.

somatic mutation

A mutation affecting SOMATIC cells that can affect only those cells and their offspring, so cannot be passed on to future generations. Such a mutation dies with the death of the individual.

somatic mutation

mutation

1. a nucleotide change, including base substitutions, insertions or deletions in DNA, or RNA in the case of some viruses, that gives rise to the mutant phenotype.

2. an animal exhibiting such change. Called also a sport.

back mutation

see reverse mutation (below).

base substitution mutation

may be a transition in which a purine-pyrimidine pair is substituted by the other purine-pyrimidine pair, or transversion in which a purine-pyrimidine pair is replaced by one of the two pyrimidine pairs.

chain termination mutation

one in which the new base sequence introduces a stop codon and thereby prematurely terminates synthesis of the polypeptide; the three mutations are also called amber (UAG), ochre (UAA) and opal (UGA).

deletion mutation

one produced by loss of nucleotides from a DNA sequence.

frame shift mutation

occur as a result of either the insertion of a new base pair or the deletion of a base pair or a block of base pairs from the DNA base sequence; these, unless they occur in 3 or multiples of 3, are most serious in that the message to the right of the frame shift is garbled.

leaky mutation

one in which the amino acid substitution only partially disrupts the function of the protein; in bacteria this is usually manifested by reduced growth rate.

mis-sense mutation

one causing an amino acid substitution in the protein.

nonsense mutation

one in which a stop codon is substituted for a codon that specifies an amino acid.

operator constitutive mutation

one or more base changes in the operator region (originally defined for the lactose operon) which stop the repressor protein from tightly binding to sequence such that it is less effective in preventing RNA polymerase from inhibiting transcription.

point mutation

a single changed base pair in the DNA of an organism which may be a base substitution, base insertion or base deletion.

mutation rate

the frequency of mutations in the population over time.

repressor-constitutive mutation

in regulation of gene expression, a mutation in the repressor protein that decreases the binding affinity of the repressor protein for the operator which leaves the gene permanently turned on.

reverse mutation

one in which the wild-type phenotype is restored; such organisms are called revertants. Called also back mutation, reversion mutation.

one in which there is a base change but because of the redundancy of the genetic code the same amino acid is coded, or one in which there is an amino acid substitution in the protein which has no detectable effect on the phenotype.

somatic mutation

a change in the DNA sequence that occurs in somatic cells, i.e. not gametes. The mechanism underlying the generation of diversity of antigen recognition by immunoglobulins and T cell receptor molecules. The fundamental cause of cancer, in which the mutation occurs spontaneously or is induced by carcinogens, such as sunlight, chemicals or viruses.

suppressor mutation

a particular type of reversion mutation in which a mutation at a second site restores the original phenotype; most simply a mutation produced by a base deletion may be restored to wild type by a proximate but independent base substitution. Called also second-site mutation.

temperature-sensitive (ts) mutation

one in which there is an altered protein that is active at one temperature, typically 86°F (30°C) and inactive at a higher temperature, usually 104 to 108°F (40 to 42°C), e.g. ts mutant virus and bacteria.

transdominant mutation

occur in genes producing diffusible products, in contrast to cis-dominant mutation in which mutations occur in regulatory sequences that are recognized by other proteins.

transition mutation

one in which the base change does not change the pyrimidine-purine orientation. See also base substitution mutation (above).

transposition mutation

one produced by the insertion of a transposable genetic element.

transversion mutation

one in which the purine-pyrimidine orientation is changed to pyrimidine-purine or vice versa. See also base substitution mutation (above).

somatic

1. pertaining to or characteristic of the body or soma.

2. pertaining to the body wall, not the viscera.

somatic afferent system

the system of sensory neurons scattered around the body and responding to pain, touch, temperature and other external stimuli.

Somatic mutations at a polynucleotide tract within RPL22, which lead to protein truncation, were previously demonstrated to occur in 52% of MSI-high endometrioid endometrial carcinomas and to correlate with a later age at diagnosis (67 vs.

Taking two very different approaches, the teams found that a surprising percentage of those sampled had acquired a subset -- some but not all -- of the somatic mutations that are present in blood cancers.

With BEAMing being one of the most sensitive technologies available today for the detection of tumor specific somatic mutations in blood samples, Sysmex Inostics' OncoBEAM(TM) services are readily available to support clinical trials and research in oncology.

She explained: "It has been generally assumed that increased levels of estrogen and progesterone in multiple pregnancies stimulate cellular proliferation in the breast, which increases accumulation of somatic mutations during cell division and leads to the development of breast cancer.

For example, between 1 and 3 genes in high-grade serous ovarian cancer or triple-negative breast cancer are subject to somatic mutations in >10% of patients with the same histopathologic subtype of disease (1, 2).

Topics include new insights from gene expression profiling into human hepatocellular carcinoma, germline and somatic mutations in colorectal cancers from patients with hereditary nonpolyposis colorectal cancer, lung cancer screening, progress in the prevention of colorectal cancer, diagnosis and therapy of long-bone adamantinomas, the effects of physical activity in protection against colorectal cancer, the importance of EGFR in tumorigenesis from preneoplastic bronchial lesions to invasive lung cancer, the usefulness of anal endosonography in the assessment of anal carcinoma, and acute phase reactants in hemodialysis and renal transplantation.

The QCI bioinformatics platform, launched earlier this year, has been expanded from interpreting NGS data on somatic mutations in solid tumor cancers to add leukemia and lymphoma testing, as well as testing for hereditary cancer indications.

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